Excavator



Dec. 7, 1948. E. DRQTT HA 2,455,474

EXCAVATOR Filed Feb. 5, 1945 4 Sheets-Sheet 1 INVENTORS ea. 7, m8. 5. A.D ROTT ETAL. 2,455,474

EXCAVATOR Filed Feb. 5, 1945 4 Sheets-Sheet 2 INVENTORS BY W he KATI'OP/VZY.

Dec. 7, DRQ-TT Er EXCAVATOR Filed Feb. 5, 1945 4 Sheets-Sheet 3 Dec. 7,1948. E. A. DROTT ETIAL EXCAVATOR 4 Sheets-Sheet 4 Filed Feb. 5, 1945INVENTOM Patented cc. 7, 1948 PAT f NT OFFEC axcava'roa WisconsinApplication February 5, 1945, Serial No. 576,286

12 (Jlaims. l

The invention relates to excavators and more particularly to a high liftmobile excavator.

One object of the invention is to provide a hydraulically operatedshovel lifting mechanism which permits disposition of the shovel orbucket directly adjacent the radiator or front portion of the tractorvehicle and a vertical lifting of the shovel to a considerableheight-without pitching forward, thus eliminating a big overhang of theshovel while carrying its load and thereby reducing the stresses andstrains on the front portions of the propelling mechanism which in thecase of the track type tractor reduces stresses and strains on the frontroller and idler. From a load transporting position the bucket carryingmechanism of this invention permits the bucket to be raised several feethigher, and during this raising movement through a linkage arrangementand without any additional hydraulic equipment the bucket is projectedseveral feet out ahead of the tractor which allows it to dump in themiddle of a truck body.

In addition to the elimination of a large overhang, a further advantageobtained by the invention is elimination of any obstruction to theoperators views while the unit is being filled and transported, as thereis then nothing ahead of him any higher than his vision, and after thebucket is raised still higher, he again has full view under the bucket.

A further object of the invention is to provide a new and improvedmounting and control of the bucket. Previously all high lift shovels,either hydraulic or cable, had a set position for the bucket both forloading and unloading. The only way positions could be changed wasmanually while the unit was standing still, and in all cases the onlyway to lift the bucket out of the ground was by lifting the entire unit.According to the present invention, the bucket is undercontinuoushydraulic control and can be moved to tilt the cutting edgedown or up to suit the varying conditions, can be dumped at any height,and either close to the tractor or several feet ahead of the same whilethe tractor is in motion or standing still.

More particularly, according to the present invention, the bucket ispivotally connected to its carrying arms which include a part that can'be brought in contact with. the ground while the bucket is turned fromits digging or scraping position to a load carrying position and maythen be raised to a dumping position. The tilting of the bucket relativeto its supporting arms permits the making of a, smooth out as thesupporting part 2 of the arms may ride on the smooth out made by thecutting edge of the bucket during the digging operation, and when thebucket is filled while traveling forward, it is not necessary to liftthe carrying arms in order to discontinue the cut or bring the cuttingedge of the bucket out of the ground but simply to roll the bucket backon its supports, thus lifting the bucket out of the ground and puttingail of the weight on the supporting arms which are then through theshoes in contact with the ground, and the bucket may then besemi-skidded or floated on the shoes to the place of disposal of thematerial and the whole assembly then lifted high enough to dump thecontents of the bucket into a receiving truck.

Another advantage of the rolling or pivotal mounting of the bucketrelative to its supporting arms is that when shoveling into a bank or a,

so-called straight face, the bucket can be tilted shaving ofi' whateverportion of the bank is desired. All operations including lifting andlowering the bucket carrying mechanism, tilting, or rolling the bucketare under complete hydraulic control at all times.

The invention further consists in the several features hereinafter setforth and more particularly defined by the claims at the conclusionhereof.

In the drawings:

Fig. 1 is a side elevation view of an excavator embodying the invention,in a digging position:

Fig. 2 is a plan view thereof, parts being broken away and parts beingshown in section;

Fig. 3 is a view similar to Fig. 1 showing the excavator in a dumpingposition and also parts thereof in dotted lines in a partly raisedposition;

Fig. 4' is a side elevation view of an excavator embodying theinvention, showing certain modifications.

Referring to the drawings, the numeral 5 designates a. tractor vehiclehere shown as a tractor having endless propelling and supporting treads6 at opposite sides of the vehicle and whose sprockets 1 are suitablymounted on a track frame 8 which is pivotally connected to a shaft 9associated with the frame ID of the vehicle, the power plant I l on thevehicle frame being suitably connected with one of the sprockets I todrive the same, but as the details of the tread structure and its drivefrom the vehicle are not here claimed as new, further descriptionthereof is deemed unnecessary.

Frame parts i2 on each side of the vehicle are mounted on brackets orframe parts l3 on the track frames 8.

The shovel or bucket I4 is mounted on a supporting structure which isnot directly connected to any of the frame parts of .the vehicle but hasa floating or semi-floating connection therewith.

This structure includes a pair of armsiipivotally connected at theirforward ends by pins It to the lower portion of the digging bucket andpivotally connected at their rearward ends by pins i8 to the upper endsof a pair of swinging links I8 pivotally connected at their lower endsby pins to the frame parts l2, thus forming a bucket supportingstructure having'a floating or semi-floating connection with a frame ofthe carrying vehicle.

For supporting this floating frame structure. there are a pair of arms2| pivotally connected at their rear ends by pins 22 to the frame partsl2 and at their forward ends by pivot pins 23 to a pair of links 24pivotally connected at their other ends by a cross bar 25 to aprojecting portion 26 of arms IE, it being noted that these arms areformed by parts 21 and 28 extending at an obtuse angle to each other, sothat when said arms are lowered, the digging bucket will be disposed atthe front of the vehicle and directly in front of the radiator for thepower plant II.

The raising and lowering of the linkage above described is accomplishedby double acting hydraulic cylinders 29, one for each of the arms 2| andoperatively connected thereto. Each cylinder 28 is pivotally mounted ona pin 30 carried by the frame part |2 at one side of the tractor, andits operating piston has its rod 3| working through a stufling box 32 atthe other end of the cylinder and pivotally connected by a pin 33 to amounting bracket 34 on-the other end portion of its arm 2|. Thecylinders 29 are in a hydraulic circuit and under the control of anysuitable operator controlled valve mechanism 35 which in known mannerpermits introduction of pressure fluid to one of the ends of thecylinders while exhausting from the other and which permits retention offluid in both ends of the cylinder to hold the piston in any desired setposition. Thus through the action of the cylinders 29, the arms 2|, andthe linkage associated therewith is raised or lowered or held in anyadjusted position and pressure may also be placed on the linkage whenthe bucket is in a digging position.

For controlling the movements of the floating linkage and for securing aforward thrust thereof as the bucket reaches its elevated position, apair of toggle links 36 are associated with each set of linkages. One ofthese links is pivotally connected at 31 tothe outer end portion of oneof the swinging links l9, and the other of these links 36 is pivotallyconnected by a pin 38 to the frame part l2. From Fig. 2 it will be notedthat the frame parts l2 include spaced plates 39 to carry the pivot pinsabove referred to.

Various forms of digging buckets l4 may be used in connection with thesupporting means heretofore described, and by way of example we haveshown two forms of buckets, that shown in Figs. 1 to 3 being a two partbucket generally similar to the bucket structure shown in our prior U.S. Letters Patent No. 2,326,338, while that shown in Fig. 4 being a onepart or tilting bucket.

Details of the structure of the bucket shown in Figs. 1 to 3 will befound in the above referred to letters patent, so need not bespecifically shown or described here, but this bucket is formed by aplow part 40 and an open ended scoop part 4| pivotally connected atspaced points to a trans- 4 verse shaft 42 carried at the top portion ofsaid plow part.

The outer ends of the arms I5 are pivotally connected by the pins It tothe lower portion of the plow part 40, and the upper portion of the plowpart 40 is pivotally connected by pins 43 to the outer ends of links 44whose inner ends 45 are pivotally connected by pins 48 to one of thearms 41 of a pair of bell crank levers 48 which are pivotally carried at49 on the arms l5 and whose other arms are pivotally connected by pins60 to the knee of the toggle links 36, said pin being a common connectorfor said links.

At spaced points, the upper end of the scoop part 4| is connected fastto the shaft 42 which carries crank arms 5| pivotally connected by links52 with the outer ends of levers 53 whose inner ends are pivotallycarried at 84 on the arms I5. At intermediate points on the levers 53,pivot pins 55 pivotally connect them withpiston rods 56 of double actinghydraulic cylinders 51 which are pivotally mounted at 58 upon the outerends of the bell crank levers 48. Reeiprocation of the rods 56 under theaction of hydraulic fluid introduced into the cylinders 51 by operationof suitable control valve mechanism 59 will act to open or close thescoop part 4|, and the movement of said valve mechanism 59 to a lappedposition will act to hold said scoop part 4| in any desired setposition. As in accordance with the aforesaid patent, it will be notedthat the scoop part 4| is in a partially open position while the plowpart 40 plows or scrapes up a load of material in r front of it, andthen as the digging progresses, the

scoop part is moved to a closed position, and the loaded bucket is thenraised as indicated by the dotted lines in Fig. 3 tea transportingposition and may then be raised to the elevated dumping position shownin said figure and the scoop part then moved to open position to dumpthe load.

The one piece bucket construction is shown in Fig. 4, and it will beobserved that the lower ends of the arms i5 are provided with shoes 60that may be brought in contact with the ground and that the lowerportion of the bucket i4 is pivotally connected by pins 6| to the outerends of the arms I5 in front of the shoes 60, thus providing a tiltablemounting for the bucket I4.

The upper end of this one part bucket is pivotally connected by pins 62to the outer curved ends of the piston rods 63 whose pistons work indouble acting hydraulic cylinders 64 pivotally carried at on the outerends'of the bell crank levers 48. With this arrangement introduction ofhydraulic pressure fluid into the back ends of the cylinder 64 whileexhausting from their front ends will tilt the scoop or bucket |4downwardly and introduction of hydraulic fluid.

into the front ends of the cylinders 84 while exhausting from'their backends will tilt the scoop upwardly, 'and lapping of the hydraulic control59 (shown in Fig. 3) will hold hydraulic fluid in both ends of saidcylinders 64 to hold the bucket or scoop in any desired angular positionrelative to its supporting arms i5. It will be noted that with this formof bucket the outer ends 66 of the arms are curved, so that the bucketmay be brought down close to the front of the tractor and the shoes 60rest on the ground just in front of the treads 6.

With this arrangement when starting to load the arms |5 are lowered tobring the shoes so in contact with the ground, and the bucket I4 is thentilted on its pivot 6| to bring its cutting edge 81 to the desireddigging angle. Then during digging by rocking the bucket 14 about itspivot under the action of the cylinders 64 the shoes 60 areautomatically lifted off of the ground by thepressure of the cuttingedge being forced down to the desired depth of cut, and then by tiltingback the bucket to a level with the shoes,

. a perfectly smooth out can be made as the shoes at the back ride onthe smooth out made by the cutting edge. When the bucket is filled whiletraveling forward, it is not necessary to lift the arms It in order todiscontinue the cut or bring the bucket out of the ground since byreversing the action of the cylinders 66 the bucket H can be rolled ortilted back against the arms is swinging it about the pivot 8! under theaction of the piston rods 83 and the cylinders 84. This rolling motionlifts the bucket off of the ground and puts all of the weight on thearms id and the shoes 60, and in this position the bucket may besemi-skidded or floated to the place of disposal of the dirt.Thereafter, the arms ii'may be raised to bring the bucket to anyelevated position and the cylinder 66 operated to tilt the bucketdownwardly to discharge the load. Also in digging into a bank or aso-called straight face the bucket it can be tilted about its pivot 86to shave off whatever portion of the bank is desired and then be tiltedback on the arms it to carry its load. In this way the bucket does nothave to be pulled upwardly against the entire resistance of the bank toreceive its load but may take successive bites in the face of the bankto remove the material therefrom. All operations including lifting andlowering the bucket carry mechanism, tilting or rolling the bucket areunder complete hydraulic control at all times through the action of thecylinders 29 and 64%.

In connection with both forms of the invention it will be noted thatwhen the arms W are lowered and the bucket is in a digging position, thelinks 36 are in an off center position (see Fig. 1) and that ashydraulic fluid is introduced into the back end of the cylinders 29raising the arms 25 about their fixed points that through the connectionof the links 2 3 with the arms iii said arms iii are raised on theirfloating pivots i8 and that the links 35 gradually move to a straightline position, but that during this movement the overhang of the loadedbucket in front of the vehicle is not materially changed and the partsassume the dotted line position shown in Fig. 3 which is a position thatmay be used for transporting the loaded bucket to a place of deposit.Thereafter, as the arms it are further raised, the links 36 move fromtheir straight line position to the full line position shown in Fig. 3,and this movement causes the links it through the breaking of the togglelinks at to swing forwardly, thus swinging the arms i forwardly to bringthe bucket to an overhanging position which is the position it assumesin its fully elevated condition, and the bucket may then be opened ortilted as heretofore described to discharge the load. The bucket is may,of course, be dumped at any elevated position, if desired, but is raisedto its high position for dumping when loading into a truck.

We desire it to be understood that this invention is not to be limitedto any particular form or arrangement of parts except in so far as suchlimitations are included in the claims.

What we claim as our invention is:

1. In an excavator, the combination with a movable support, of a diggingbucket, a supporttion with a movable support, of a load receivingingstructure for said bucket mounted to float relative to said support, andraising and lowering means for said supporting structure comprising armspivoted at a fixed point on said support and operatively connected to anintermediate portion of said supporting structure and hydraulicallyoperated cylinders operatively connected with said arms.

2. In a load handling apparatus, the combination with a movable support,of a load receiving means, supporting arms for said load receivingmeans, links pivotally connecting said armswith said support to form afloating connection therewith, raising and lowering means for said arms,and linkage means connecting said first named links with said supportand with said arms to control their movement and cause said arms to moveforwardly as they are raised to a position for dumping the said loadreceiving means.

3. In a load handling apparatus, the combinameans, supporting arms forsaid load receiving means, links pivotally connecting said arms withsaid support to form a floating connection therewith, raising andlowering means for said arms. and means including toggle linksconnecting said first named links with said support and said arms tocontrol their movement and cause said arms to move forwardly as they areraised to a position for dumping said lead receiving means.

4. In a load handling apparatus, the combination with a movable support,of a load receiving means, supporting arms for said load receivingmeans, links pivotally connecting said arms with said support to form afloating connection therewith, arms pivotally mounted on said supportand operatively connected to said supporting arms, hydraulic cylinderscontrolling the movement of saidlast named arms, and linkage meansconnecting said links with said support and to said arms to controltheir movement and cause them to move said supporting arms and said loadreceiving means forwardly as they are raised to a position for dumpingload receiving means.

5. In an excavator, the combination with a movable support, of a diggingbucket, supporting arms for said bucket, links pivotally connecting saidarms with said support to form a floating connection therewith, armspivotally mounted on said support and operatively connected to saidsupporting arms, hydraulic cylinders controlling the movement of saidlast named arms, a pair of toggle links connecting the upper portions ofsaid first named links with said support and controlling their movement,bell crank levers pivotally mounted on said supporting arms and havingone of their arms pivotally connected to the knees of said toggle links,and bucket dumping mechanism including hydraulic cylinders carried bythe other arms of said bell crank levers.

6. In an excavator, the combination with a movable support, of atiltable digging bucket, supporting means for said bucket including armspivotally connected to the lower portion of said bucket and havingground engaging shoes back of their pivotal connection with the bucketfor assisting in the making of a smooth out, positively acting means fortilting the bucket about its pivotal connections with said arms duringdigging, and means for raising and lowering said arms.

7. In an excavator, the combination with a movable support, of 'atiltable digging bucket, supporting means for said bucket including armspivotally connected to the lower portion of said bucket and havingground engaging shoes back of their pivotal connection with the bucket,positively acting means for tilting the bucket to vary its digging angleduring digging and to swing the .loaded bucket back onto said arms, andmeans Iior raising and lowering said arms.

8. In an excavator, the combination with a. movable support, of atiltable digging bucket, supporting means for said bucket including armspivotally connected to the lower portion of the said bucket and havinggroundengaging shoes back of said pivotal connections, hydraulicallyoperated means carried by said arms and operatively connected to theupper portion of the bucket for tilting said bucket about its pivotandholding it in difierent positions of tilt, and means for raising andlowering said arms.

9. In an excavator, the combination with a movable support, of a diggingbucket, support- 8 said first named links forwardly to extend said armsbeyond their initial position.

ing arms 'for said bucket, links pivotally connecting said arms withsaid support to form a floating connection therewith, arms pivotallymounted on said support and operatively connected to said supportingarms, a pair of toggle links operatively connecting said first namedlinks with said support, and means connecting the knees of said togglelinks to said supporting arms to shift the position of said first namedlinks as said arms are moved upwardly and swing said links forwardly asthe bucket reaches its upper position to project said arms forwardlyfrom their initial lowered position relative to said support.

10. In an excavator, the combination with a movable support, ofimplement supporting arms, links pivotally connecting said arms withsaid support to form a floating connection therewith, said arms havingupwardly extending portions, links pivotally connecting said arms withsaid support to form a floating connection therewith, lifting armspivotally mounted on said support, links operatively connecting theouter ends of said arms with said extensions of said implementsupporting arms, means for raising and lowering said lifting arms, apair of toggle links connecting said first named links with saidsupport, means operatively connecting the knees of said toggle links tosaid supporting arms whereby to break the knee of said toggle links assaid supporting arms are moved to a raised position and project 11. In amaterial handling device, the combination with a movable support,implement supporting arms, linkage pivotally connecting said arms withsaid support to form a floating connection therewith, raising andlowering means for said arms, toggle links connecting said first namedlinkage with said support, and means connected to the knees or saidtoggle links for breaking the toggle as said supporting arms are movedupwardly and thereby moving said first named linkage to a position toproject said arms forwardly from their initial position.

12. In a load handling apparatus, the combination with a movablesupport, of a load-receivin means, a supporting structure for saidloadreceiving means, a movable mounting for said structure to allow itto float relative to said support, raising and lowering means for saidsupporting structure having a fixed pivotal mounting on said support,and linkage means between said movable mounting, said structure and saidsupport to project said load-receiving means forwardly as it moves to araised dumping position.

EDWARD A. DRO'I'I. JOSEPH H. KERBER.

REFERENCES CITED The following reierences are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,146,807 Ferari Feb. 14, 19392,295,917 Schwan 1 Sept. 15, 1942 2,303,852 Linn Dec. 1, 1942 2,306,474Tieslau Dec. 29, 1942 2,317,075 McFarland Apr. 20, 1943 2,319,921 Dooleyet a1 May 25, 1943 2,326,338 Drott et a]. Aug. 10, 1943 2,338,361 ShinnJan. 4, 1944 2,345,620 Mork Apr. 4, 1944 2,348,796 Ferwerda et al May16, 1944 2,387,656 Gledhill Oct. 23, 1945 2,393,299 Denning Jan. 22,1946 2,413,096 Barker Dec. 24, 1946

